The Zero Hour mission (final Mar Sara mission) is the first
mission to present the player with some more difficult achievements and challenges.
In this article, I will be discussing how to unlock each achievements (including the infamous Zero Hour Hard
achievement: "The Best Defense). I have separated the Zero Hour Brutal
Guide into another article, since the Zero Hour hard achievement requires so much explanation.
Starcraft 2 Zero Hour Hard Achievement: The Best Defense
To unlock "The Best Defense", the player must kill 4 Hatcheries (Lairs are included) before the time expires.
The player does not have to survive and complete the mission (although you should be able to).
This achievement can be quite challenging. I will be giving some tasks you have to complete by certain times in
the mission below. In general, we are going to make as many Marines and Medics as possible, and go in on the enemy
base at the last second. Here are the specifics:
As soon as the match starts, start training 2 SCVs and set the rally point to the mineral line.
Next, use the Salvage command to get an extra 200 minerals from the 2 Bunkers closest to your main Command
Queue up 2 marines to be trained at your Barracks as well.
Finally, start researching +1 Weapons as soon as the game starts.
Pull off 1 SCV and build a second Bunker by the left entrance to your base (be sure not to block the
As soon as that Bunker finishes, have that SCV build a second Bunker by the right entrance to your
Load all your Marines into the Bunkers.
During the first wave, you will get a free SCV that will start repairing your Bunkers on the left side.
Leave it there.
Keep training Marines and SCVs as you build your finish building bunkers.
When you first get the message that friendly units need to be saved, build a Turret in between the two
turrets that are already at the front of your base.
Once the turret starts being built, unload all your Marines from the right set of Bunkers and move in (you
will be attacked from the left while you are doing the saving). You should have around 15 Marines at this
You can easily save these Marines and grab some free resources in the mean time.
After saving the units, return to your base and build a Tech Lab and Reactor on each Barracks.
Make sure you have built around 20 SCVs at your main (all harvesting), make sure that you place a few near
the entrance to your base (about 5 total is ideal, though it may take some time to build up to that).
Keep training units (Marines and Medics and build a third Barracks. Attach a Reactor and start training
Marines out of this one.
As soon as you get the second call for help, take the right side of units and rescue (this will prevent
your base from being attacked while you rescue).
Return to your base and keep training units after the second rescue.
Research +1 Armor upgrade at the Engineering Bay.
At this point, split up your free-standing troops, so you have half your Marines and Medics at each
entrance to your base.
@9:30 time remaining: Both sides will get hit.
Build a third Bunker at the right entrance and place 4 Marines inside.
As soon as you get the message for the third rescue, move in with all your units, aside from the 12 Marines
in the right side Bunkers. Pull the units from your left side Bunkers and take them with you.
Rescue the Marines and return to your base.
Use these extra resources to continuously pump out Marines and Medics.
At about 5:45-6:15 remaining, gather up all your army (aside for the 20 Marines in Bunkers) and move
in on the west side base, right beside where you made your Third rescue. If you continuously
trained units at your three Barracks (2 pumping Marines and 1 Medics), you should have a Supply Count of
With an army of about 105 supply count, you should be able to take out the Western base.
You are likely to incur some heavy losses, but that is expected. The Western Base actually contains 3
Hatcheries, so you are a lot closer to unlocking the achievement then you might think at first.
After taking out the Western base, grab ALL of your units and if the enemy breaks through, just lift off
any buildings you have remaining.
Fortunately, the north-west base is barely guarded, and is easy to take out with only about 30 Marines and
a handful of medics. Kill the 4th Hatchery here and pull back into your base.
If you want to finish out the mission successfully, you can just pull back to the top of your main ramp
with all of your units and survive easily.
Yes, it is a lengthy description, but the challenge the Zero Hour Hard achievement is not too bad. The key
points are to always be training Marines and Medics, and pull off all the rescues with minimal casualties.
The biggest mistake people make is attacking the first base without enough units. You need as big of an army as
you can muster, as there really are a ton of units and Spine Crawlers in each base.
As soon as you take out the first base, you have the achievement down. Just move in with all your units on the
North-west base and you complete the Best Defense achievement easily.
The North-East base is not worth going for and extremely well defended. It has a lot more units and Spine
Crawlers, so you should avoid going there (unless you are bored and looking for an extra challenge).
The Best Defense... Video Walkthrough
If you are having trouble unlocking this achievement, this video walkthrough will make things a lot clearer for
There are two more achievements aside from the Zero Hour hard achievement. Here is the list of other
achievements and how to unlock them:
Zero Hour - Complete all the mission objectives. This achievement unlocks automatically when
you beat the mission, so I think no explanation is necessary.
Hold The Line - Complete the Zero Hour Mission on Normal Difficulty without losing or salvaging
any buildings. This achievement is pretty easy, but just in case, here is a guide:
Hold The Line - Zero Hour Achievement Guide
Since no buildings are allowed, you have to rely on units to defend your base. This will prevent your buildings
from being targeted. You have to do this in normal mode (next to impossible to complete in Hard
Mode). Here is how you do it:
Start out with the same style as mentioned in The Best Defense guide. Start out by building a bunker at
each ramp and training Marines, SCVs, and +1 armor.
Keep making SCVs and Marines.
As soon as you get the call for help from the first group, build a Turret in between the 2 turrets that
already exist on your front lines (Mutalisks hit here shortly).
Send in 8 Marines from the right side to go rescue the first group. Rescue them and return to the right
Keep training SCVs. Eventually, park 2 SCVs at each entrance and 1 SCV by the Turrets.
Build no more Bunkers or Turrets - the less buildings you have the less things you have to guard!
Build a third Barracks with a Reactor as soon as you can afford it. Keep training Marines and Medics.
As soon as you get the call for the second rescue, take your entire army (aside from the 16
Marines in the two sets of Bunkers and go rescue the troops.
After the rescue, park these troops in front of your left set of Bunkers. Keep training Marines and Medics
and place this army in front of your right set of Bunkers.
As soon as you get the 3rd call for help, immediately move your units out and rescue the troops. If you do
it right away, you literally do not have to fight any Zerg to pull off the rescue. Make these new units part of
the left-side army.
Your left side army should now be complete and consist of ~30+ Marines and 8+ Medics. Park it in front of
the Bunkers and leave them there.
Keep training units to bolster your right side army.
At about 2 minutes and 20 seconds, pull 80% of your SCVs off and split them up between each set of Bunkers.
You should not need them, but just in case they will repair.
When the Zerg armies do make their final push, they should not break past your Marines and Medics. In normal
mode, no Zerg units spawn inside your base, so you do not have to worry about defending the inside of your base
Just get a decent sized army in front of each set of Bunkers, leave plenty of SCVs out to repair, and you will
unlock this Zero Hour achievement easily.